This invention relates to composite impellers and propellers for driving fluids.
Conventional high precision metal impellers and propellers are manufactured as a single unit using a five axis machine to machine the blade and hub and a shroud is separately machined and then welded to the tips of the vanes. Composite impellers and propellers are conventionally molded as a single monolithic structure which is less costly but also less precise than the five axis machining method for metal impellers and propellers.
The Shingai U.S. Pat. No. 6,126,395 discloses an axial fan assembled from two components formed by injection molding of resin material. One component is an impeller having a plurality of radial vanes molded integrally with the central hub and the other component is a cylindrical member attached to an axial shaft and adapted to be attached to the hub and the vane members to drive the fan.
In the By et al. U.S. Pat. No. 5,431,536 a torque converter stator has blades which are integral with inner and outer rim portions and formed by molding of resin material.
The Sekine U.S. Pat. No. 5,655,875 also discloses a plastic torque converter stator made of resin material and having an outer rim and a hub integrally molded with vanes which extend between those components.
The insertable stator vane assembly of the Furseth et al. U.S. Pat. No. 5,547,342 includes stator vanes which are molded of non-metallic composite material and secured to a metallic inner hub and to an outer casing made of metallic material.
The Rasch et al. U.S. Pat. No. 5,813,832 discloses a turbine engine vane segment consisting of a metallic air foil which is mounted between inner and outer metal bands.